Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-01-17

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add initial BPF map offloading for nfp driver. Currently only
   programs were supported so far w/o being able to access maps.
   Offloaded programs are right now only allowed to perform map
   lookups, and control path is responsible for populating the
   maps. BPF core infrastructure along with nfp implementation is
   provided, from Jakub.

2) Various follow-ups to Josef's BPF error injections. More
   specifically that includes: properly check whether the error
   injectable event is on function entry or not, remove the percpu
   bpf_kprobe_override and rather compare instruction pointer
   with original one, separate error-injection from kprobes since
   it's not limited to it, add injectable error types in order to
   specify what is the expected type of failure, and last but not
   least also support the kernel's fault injection framework, all
   from Masami.

3) Various misc improvements and cleanups to the libbpf Makefile.
   That is, fix permissions when installing BPF header files, remove
   unused variables and functions, and also install the libbpf.h
   header, from Jesper.

4) When offloading to nfp JIT and the BPF insn is unsupported in the
   JIT, then reject right at verification time. Also fix libbpf with
   regards to ELF section name matching by properly treating the
   program type as prefix. Both from Quentin.

5) Add -DPACKAGE to bpftool when including bfd.h for the disassembler.
   This is needed, for example, when building libfd from source as
   bpftool doesn't supply a config.h for bfd.h. Fix from Jiong.

6) xdp_convert_ctx_access() is simplified since it doesn't need to
   set target size during verification, from Jesper.

7) Let bpftool properly recognize BPF_PROG_TYPE_CGROUP_DEVICE
   program types, from Roman.

8) Various functions in BPF cpumap were not declared static, from Wei.

9) Fix a double semicolon in BPF samples, from Luis.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 349 insertions, 0 deletions

diff --git a/kernel/fail_function.c b/kernel/fail_function.c
new file mode 100644
index 000000000000..21b0122cb39c
--- /dev/null
+++ b/kernel/fail_function.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fail_function.c: Function-based error injection
+ */
+#include <linux/error-injection.h>
+#include <linux/debugfs.h>
+#include <linux/fault-inject.h>
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+static int fei_kprobe_handler(struct kprobe *kp, struct pt_regs *regs);
+
+struct fei_attr {
+        struct list_head list;
+        struct kprobe kp;
+        unsigned long retval;
+};
+static DEFINE_MUTEX(fei_lock);
+static LIST_HEAD(fei_attr_list);
+static DECLARE_FAULT_ATTR(fei_fault_attr);
+static struct dentry *fei_debugfs_dir;
+
+static unsigned long adjust_error_retval(unsigned long addr, unsigned long retv)
+{
+        switch (get_injectable_error_type(addr)) {
+        case EI_ETYPE_NULL:
+                if (retv != 0)
+                        return 0;
+                break;
+        case EI_ETYPE_ERRNO:
+                if (retv < (unsigned long)-MAX_ERRNO)
+                        return (unsigned long)-EINVAL;
+                break;
+        case EI_ETYPE_ERRNO_NULL:
+                if (retv != 0 && retv < (unsigned long)-MAX_ERRNO)
+                        return (unsigned long)-EINVAL;
+                break;
+        }
+
+        return retv;
+}
+
+static struct fei_attr *fei_attr_new(const char *sym, unsigned long addr)
+{
+        struct fei_attr *attr;
+
+        attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+        if (attr) {
+                attr->kp.symbol_name = kstrdup(sym, GFP_KERNEL);
+                if (!attr->kp.symbol_name) {
+                        kfree(attr);
+                        return NULL;
+                }
+                attr->kp.pre_handler = fei_kprobe_handler;
+                attr->retval = adjust_error_retval(addr, 0);
+                INIT_LIST_HEAD(&attr->list);
+        }
+        return attr;
+}
+
+static void fei_attr_free(struct fei_attr *attr)
+{
+        if (attr) {
+                kfree(attr->kp.symbol_name);
+                kfree(attr);
+        }
+}
+
+static struct fei_attr *fei_attr_lookup(const char *sym)
+{
+        struct fei_attr *attr;
+
+        list_for_each_entry(attr, &fei_attr_list, list) {
+                if (!strcmp(attr->kp.symbol_name, sym))
+                        return attr;
+        }
+
+        return NULL;
+}
+
+static bool fei_attr_is_valid(struct fei_attr *_attr)
+{
+        struct fei_attr *attr;
+
+        list_for_each_entry(attr, &fei_attr_list, list) {
+                if (attr == _attr)
+                        return true;
+        }
+
+        return false;
+}
+
+static int fei_retval_set(void *data, u64 val)
+{
+        struct fei_attr *attr = data;
+        unsigned long retv = (unsigned long)val;
+        int err = 0;
+
+        mutex_lock(&fei_lock);
+        /*
+         * Since this operation can be done after retval file is removed,
+         * It is safer to check the attr is still valid before accessing
+         * its member.
+         */
+        if (!fei_attr_is_valid(attr)) {
+                err = -ENOENT;
+                goto out;
+        }
+
+        if (attr->kp.addr) {
+                if (adjust_error_retval((unsigned long)attr->kp.addr,
+                                        val) != retv)
+                        err = -EINVAL;
+        }
+        if (!err)
+                attr->retval = val;
+out:
+        mutex_unlock(&fei_lock);
+
+        return err;
+}
+
+static int fei_retval_get(void *data, u64 *val)
+{
+        struct fei_attr *attr = data;
+        int err = 0;
+
+        mutex_lock(&fei_lock);
+        /* Here we also validate @attr to ensure it still exists. */
+        if (!fei_attr_is_valid(attr))
+                err = -ENOENT;
+        else
+                *val = attr->retval;
+        mutex_unlock(&fei_lock);
+
+        return err;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fei_retval_ops, fei_retval_get, fei_retval_set,
+                         "%llx\n");
+
+static int fei_debugfs_add_attr(struct fei_attr *attr)
+{
+        struct dentry *dir;
+
+        dir = debugfs_create_dir(attr->kp.symbol_name, fei_debugfs_dir);
+        if (!dir)
+                return -ENOMEM;
+
+        if (!debugfs_create_file("retval", 0600, dir, attr, &fei_retval_ops)) {
+                debugfs_remove_recursive(dir);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+static void fei_debugfs_remove_attr(struct fei_attr *attr)
+{
+        struct dentry *dir;
+
+        dir = debugfs_lookup(attr->kp.symbol_name, fei_debugfs_dir);
+        if (dir)
+                debugfs_remove_recursive(dir);
+}
+
+static int fei_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
+{
+        struct fei_attr *attr = container_of(kp, struct fei_attr, kp);
+
+        if (should_fail(&fei_fault_attr, 1)) {
+                regs_set_return_value(regs, attr->retval);
+                override_function_with_return(regs);
+                /* Kprobe specific fixup */
+                reset_current_kprobe();
+                preempt_enable_no_resched();
+                return 1;
+        }
+
+        return 0;
+}
+NOKPROBE_SYMBOL(fei_kprobe_handler)
+
+static void *fei_seq_start(struct seq_file *m, loff_t *pos)
+{
+        mutex_lock(&fei_lock);
+        return seq_list_start(&fei_attr_list, *pos);
+}
+
+static void fei_seq_stop(struct seq_file *m, void *v)
+{
+        mutex_unlock(&fei_lock);
+}
+
+static void *fei_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        return seq_list_next(v, &fei_attr_list, pos);
+}
+
+static int fei_seq_show(struct seq_file *m, void *v)
+{
+        struct fei_attr *attr = list_entry(v, struct fei_attr, list);
+
+        seq_printf(m, "%pf\n", attr->kp.addr);
+        return 0;
+}
+
+static const struct seq_operations fei_seq_ops = {
+        .start  = fei_seq_start,
+        .next   = fei_seq_next,
+        .stop   = fei_seq_stop,
+        .show   = fei_seq_show,
+};
+
+static int fei_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &fei_seq_ops);
+}
+
+static void fei_attr_remove(struct fei_attr *attr)
+{
+        fei_debugfs_remove_attr(attr);
+        unregister_kprobe(&attr->kp);
+        list_del(&attr->list);
+        fei_attr_free(attr);
+}
+
+static void fei_attr_remove_all(void)
+{
+        struct fei_attr *attr, *n;
+
+        list_for_each_entry_safe(attr, n, &fei_attr_list, list) {
+                fei_attr_remove(attr);
+        }
+}
+
+static ssize_t fei_write(struct file *file, const char __user *buffer,
+                         size_t count, loff_t *ppos)
+{
+        struct fei_attr *attr;
+        unsigned long addr;
+        char *buf, *sym;
+        int ret;
+
+        /* cut off if it is too long */
+        if (count > KSYM_NAME_LEN)
+                count = KSYM_NAME_LEN;
+        buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        if (copy_from_user(buf, buffer, count)) {
+                ret = -EFAULT;
+                goto out;
+        }
+        buf[count] = '\0';
+        sym = strstrip(buf);
+
+        mutex_lock(&fei_lock);
+
+        /* Writing just spaces will remove all injection points */
+        if (sym[0] == '\0') {
+                fei_attr_remove_all();
+                ret = count;
+                goto out;
+        }
+        /* Writing !function will remove one injection point */
+        if (sym[0] == '!') {
+                attr = fei_attr_lookup(sym + 1);
+                if (!attr) {
+                        ret = -ENOENT;
+                        goto out;
+                }
+                fei_attr_remove(attr);
+                ret = count;
+                goto out;
+        }
+
+        addr = kallsyms_lookup_name(sym);
+        if (!addr) {
+                ret = -EINVAL;
+                goto out;
+        }
+        if (!within_error_injection_list(addr)) {
+                ret = -ERANGE;
+                goto out;
+        }
+        if (fei_attr_lookup(sym)) {
+                ret = -EBUSY;
+                goto out;
+        }
+        attr = fei_attr_new(sym, addr);
+        if (!attr) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        ret = register_kprobe(&attr->kp);
+        if (!ret)
+                ret = fei_debugfs_add_attr(attr);
+        if (ret < 0)
+                fei_attr_remove(attr);
+        else {
+                list_add_tail(&attr->list, &fei_attr_list);
+                ret = count;
+        }
+out:
+        kfree(buf);
+        mutex_unlock(&fei_lock);
+        return ret;
+}
+
+static const struct file_operations fei_ops = {
+        .open =         fei_open,
+        .read =         seq_read,
+        .write =        fei_write,
+        .llseek =       seq_lseek,
+        .release =      seq_release,
+};
+
+static int __init fei_debugfs_init(void)
+{
+        struct dentry *dir;
+
+        dir = fault_create_debugfs_attr("fail_function", NULL,
+                                        &fei_fault_attr);
+        if (IS_ERR(dir))
+                return PTR_ERR(dir);
+
+        /* injectable attribute is just a symlink of error_inject/list */
+        if (!debugfs_create_symlink("injectable", dir,
+                                    "../error_injection/list"))
+                goto error;
+
+        if (!debugfs_create_file("inject", 0600, dir, NULL, &fei_ops))
+                goto error;
+
+        fei_debugfs_dir = dir;
+
+        return 0;
+error:
+        debugfs_remove_recursive(dir);
+        return -ENOMEM;
+}
+
+late_initcall(fei_debugfs_init);